Rinse enoki, trim the root, and separate strands. Dice tomatoes and slice the scallions.
Warm oil in a medium pot over medium heat.
Sauté garlic and ginger for 30 seconds until fragrant.
Stir in tomato paste and cook 1 minute. Add tomatoes and a little salt; cook 3–4 minutes until juicy.
Pour in vegetable broth and bring to a gentle boil.
Season with soy sauce, sugar, white pepper, and rice vinegar.
Add enoki mushrooms and simmer 2–3 minutes until just tender.
Turn off heat. Stir in sesame oil and half the scallions; adjust salt to taste.
Ladle into bowls and garnish with remaining scallions and cilantro.